The Supreme Court almost never says why it refuses to take a case. On Monday, however, when the court denied a petition from the man convicted in Calhoun v. United States, Justice Sonia Sotomayor, joined by Justice Stephen Breyer, issued a rare explanatory statement.

One part of the trial record was so ugly that they wanted to make clear what the rejection didnot mean. Justice Sotomayor began, “I write to dispel any doubt whether the court’s denial of certiorari should be understood to signal our tolerance of a federal prosecutor’s racially charged remark. It should not.”

Charles Calhoun, who is black, was convicted and sentenced for possession of cocaine with intent to distribute it and for possession of a firearm while drug-trafficking. As Justice Sotomayor recounted, the main issue in the case was whether Mr. Calhoun was simply along for a ride when a friend and some others tried to buy cocaine from D.E.A. agents working undercover, or actually knew what they were planning to do.